Frederick pearce



(No Model.)

P. PEARCE.

ELECTRIC MOTOR.

No. 540,456. Patented June 4 ,1895.

UNITED STATES PATENT OFFICE.

FREDERICK PEARCE, OF NEW YORK, N. Y.

ELECTRIC MOTOR.

SPECEFICATION forming part of Letters Patent No. 540,456, dated June 4, 1895.

Application filed December 3, 1890. Serial No. 378.424:- (No model.)

To all 2072 0172, it may concern:

Be it known that I, FEEDEnIoK PEARCE, a citizen of the United States, residing in the city, county, and State of New York, have invented a new and usefullmprovement in Electric Motors, of which the following is aspeciiication.

My invention relates to electric motors wherein the electric current acts through a pair of electro-magnets and a rotatable armature moving across the projecting ends of the cores of said magnets. Heretofore in these devices the electric circuit has been made and broken by a commutator upon the rotatable armature shaft and brushes bearing thereon. My invention consists in a mechanism for making and breaking the electric circuit in such electric motors, dispensing with the commutator and brushes.

My improvement consists of a spring vibrating arm connected at one end to the frame of the machine and set at right angles to the armature shaft. This vibrating arm is operated by a square or manysided hard metal block upon the rotatable armature shaft. The free end of the vibrating arm carries one contact point and an insulating block connected to the frame carries the other contact point. The electric current passes from the line through the electro magnets exciting the armature, thence to the insulated contact, and through the vibrating arm to the frame of the machine and to the line.

My improvements are especially adapted to light motors for operating rotating show stands in store windows, and other devices.

In the drawings, Figure 1 is an elevation of my improved motor. Fig. 2 is a plan of the same, and Fig. 3 is a sectional plan at the line so or of Fig. 1.

a represents a base of metal to which an auxiliary base plate a is connected.

The electro-magnets b b and their connecting base bar b are secured to the base plate a and the binding posts 0 c are also secured to the plate a.

The vertical posts d d of the frame are secured at their bases to the plate a and a bridge bar a extending above the electro magnets Z) Z) is connected to the top of the posts d d to form the frame.

The vertically placed rotatable shaft f is pivoted atits ends in the plate a, and bridge bar 6 respectively and said shaft carries the four armed armature g which moves over the projecting ends of the cores of the electro magnets b b. The shaftf above the armature g carries a square or many sided hard metal block 72, and a pinion 2' to be hereinafter described.

The vibrating arm is composed of the arm 7t and spring plate It at one end, and this is connected to a bracket 6 on the bar 6 and the free end of the arm it carries one contact point 5. An insulating block Z of hard rubber or similar material is connected to the under side of the bar e adjacent to the free end of the arm It. A plate Z is secured to the back of the block Z by. ascrew passingthrough the block Z, and passing through this plate and through an opening in the block Z is an adjustable screw m the reduced end of which projects from the face of the block Z and makes the second contact point 7.

The line and conductor wires 8 are connected to the insulated binding post 0 and pass to and through the electro magnets and from them to the plate Z of the block Z and the electric current passes by this path to the plate Z and screw m and by the contacts '7 and 5 through the vibrating arm to the frame parts 6 d o, and to the second binding post 0 and to the line wire 9.

The electric current is broken by the rotation of the block h the rounded corners of said block forcing the arm outwardly separating the contact points 5, 7 the spring 70' returning the arm 7; to a normal position and bringing the points 5, 7, together. I have shown in the drawings a four sided block h and a four bar armature and the parts are so positioned that the circuitis made and broken four times in each complete revolution of the armature. The number of sides to the block h and the number of bars to the armature must in all cases agree.

I have shown a shaft 01 pivoted at its ends in the plate a and bar 6 and this shaft a carries a toothed wheel n meshing with the pinion 4. and said shaft and wheel are rotated by the armature shaft and in turn operate devices to which motion is to be given, such for instance as rotating show stands for store windows and on which stands goods are displayed. A pin 0 prevents the accidental outward movement of the vibrating arm to too great an extent.

I do not claim a rotary shaft and armature with four arms, nor a circuit closing spring and commutator wheel, as these have been used. I am also aware that contact points have been used in finger keys and other electrio devices. In the present invention the vibrating arm acts by its leverage and inertia to promote the uniformity of action in closing and breaking the circuit, and the block FREDERICK PEARCE.

Witnesses:

GEO. T. PINCKNEY, HAROLD SERRELL. 

